U.S. patent number 10,104,568 [Application Number 15/191,089] was granted by the patent office on 2018-10-16 for periodic channel state information reporting for enhanced carrier aggregation.
This patent grant is currently assigned to QUALCOMM Incorporated. The grantee listed for this patent is QUALCOMM Incorporated. Invention is credited to Wanshi Chen, Peter Gaal.
United States Patent |
10,104,568 |
Chen , et al. |
October 16, 2018 |
Periodic channel state information reporting for enhanced carrier
aggregation
Abstract
Methods, systems, and devices for wireless communication are
described. A user equipment (UE) may detect the size of a payload
for reporting hybrid automatic repeat request (HARQ) feedback for
transmissions on a set of component carriers (CCs) and may
determine whether a scheduling request (SR) and/or a periodic
channel state information (P-CSI) report is present. The UE may
compare a size of an uplink control message, which may include a
HARQ payload size and a payload for the SR or P-CSI report, with a
threshold to select an uplink control format. The selected uplink
control format maybe associated with a large number of CCs if the
uplink control message has a payload size above a threshold. The UE
may also use a configuration for transmitting two or more P-CSI
reports during a subframe for CCs of a carrier aggregation (CA)
configuration. P-CSI reports due for transmission during a given
subframe.
Inventors: |
Chen; Wanshi (San Diego,
CA), Gaal; Peter (San Diego, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
QUALCOMM Incorporated |
San Diego |
CA |
US |
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Assignee: |
QUALCOMM Incorporated (San
Diego, CA)
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Family
ID: |
56369226 |
Appl.
No.: |
15/191,089 |
Filed: |
June 23, 2016 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20170006491 A1 |
Jan 5, 2017 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62187034 |
Jun 30, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04J
11/005 (20130101); H04L 5/0055 (20130101); H04B
7/0626 (20130101); H04L 1/1861 (20130101); H04W
74/004 (20130101); H04L 5/001 (20130101); H04L
1/1812 (20130101); H04W 24/10 (20130101); H04B
7/024 (20130101); H04L 1/1671 (20130101); H04W
72/1226 (20130101); H04W 72/0413 (20130101); H04L
1/1864 (20130101); H04L 5/0092 (20130101) |
Current International
Class: |
H04W
24/10 (20090101); H04L 1/16 (20060101); H04W
74/00 (20090101); H04J 11/00 (20060101); H04B
7/06 (20060101); H04B 7/024 (20170101); H04L
5/00 (20060101); H04L 1/18 (20060101); H04W
72/12 (20090101); H04W 72/04 (20090101) |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
ISA/EP, International Search Report and Written Opinion of the
International Searching Authority, Int'l Application No.
PCT/US2016/039364, dated Dec. 1, 2016, European Patent Office,
Rijswijk, NL, 18 pgs. cited by applicant .
Nokia Networks, "Dynamic Adaptation of HARQ-ACK Feedback Size and
PUCCH Format", 3GPP TSG-RAN WG1 Meeting #81, R1-152810, Fukuoka,
Japan, May 25-29, 2015, 3 pgs., XP050969963, 3rd Generation
Partnership Project. cited by applicant .
China UNICOM, "PUCCH Format Enhancements Considering ACK/NACK
Payload Size," 3GPP TSG RAN WG1 Meeting #81, R1-153280, Fukuoka,
Japan, May 25-29, 2015, 2 pgs., XP050973868, 3rd Generation
Partnership Project. cited by applicant .
ISA/EPO, Partial International Search Report of the International
Searching Authority, Int'l App. No. PCT/US2016/039364, dated Oct.
10, 2016, European Patent Office, Rijswijk, NL, 9 pgs. cited by
applicant.
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Primary Examiner: Wong; Warner
Attorney, Agent or Firm: Holland & Hart LLP
Parent Case Text
CROSS REFERENCES
The present application for patent claims priority to U.S.
Provisional Patent Application No. 62/187,034 by Chen et al.,
entitled "Periodic Channel State Information Reporting for Enhanced
Carrier Aggregation," filed Jun. 30, 2015, assigned to the assignee
hereof.
Claims
What is claimed is:
1. A method of wireless communication, comprising: detecting, by a
mobile device, a size of a hybrid automatic repeat request (HARQ)
payload for reporting, in a subframe, HARQ feedback associated with
transmissions on a plurality of component carriers (CCs);
determining, by the mobile device, that at least one of a
scheduling request (SR), a periodic channel state information
(P-CSI) report, or a combination thereof is to be included in the
subframe; selecting, by the mobile device, a physical uplink
control channel (PUCCH) format from a set of PUCCH formats based at
least in part on a comparison of a size of an uplink control
message with a threshold, wherein the uplink control message
comprises the HARQ payload and a payload for at least one of the SR
or the P-CSI report; and transmitting, by the mobile device, the
uplink control message in the subframe using the selected PUCCH
format.
2. The method of claim 1, wherein the set of PUCCH formats
comprises a first set of PUCCH formats associated with reporting
HARQ feedback for one CC, a second set of PUCCH formats associated
with reporting HARQ feedback for up to five CCs, or a third set of
PUCCH formats associated with reporting HARQ feedback for more than
five CCs.
3. The method of claim 1, wherein when the size of the uplink
control message is greater than the threshold, selecting the PUCCH
format comprises selecting, by the mobile device, a PUCCH format
having a greater capacity than at least one other PUCCH format from
the set of PUCCH formats.
4. The method of claim 3, wherein the threshold has a size of 22
bits.
5. The method of claim 1, further comprising: multiplexing the HARQ
payload with P-CSI reports for two or more CCs configured for the
UE, wherein determining that at least one of an SR or a P-CSI
report is to be included in the subframe comprises identifying the
P-CSI reports for the two or more CCs configured for the UE.
6. The method of claim 1, wherein the SR is determined to be
present and the uplink control message comprises the HARQ payload
and a payload for the SR.
7. The method of claim 1, wherein the SR and the P-CSI report are
determined to be present and the uplink control message comprises
the HARQ payload, a payload for the SR, and a payload for the P-CSI
report.
8. The method of claim 1, wherein the P-CSI report comprises a
report from at least one P-CSI process from a plurality of P-CSI
processes for a CC configured for the UE, a report from a P-CSI
process for at least one P-CSI subframe set from a plurality of
P-CSI subframe sets for a CC configured for the UE, or a
combination thereof.
9. The method of claim 1, wherein determining that at least one of
the SR or the P-CSI report is to be included in the subframe
comprises: determining to report a subset of P-CSI reports from a
set of P-CSI reports.
10. The method of claim 9, wherein determining to report a subset
of P-CSI reports from a set of P-CSI reports comprises:
prioritizing P-CSI reports based on P-CSI report types, the
prioritizing performed within a CC configured for the UE, or across
CCs configured for the UE, or a combination thereof.
11. The method of claim 9, wherein determining to report a subset
of P-CSI reports from a set of P-CSI reports comprises:
prioritizing based on P-CSI report types, followed by prioritizing
based on a CSI process identification, followed by prioritizing
based on a CC index, followed by prioritizing based on a subframe
set index.
12. The method of claim 1, further comprising: receiving signaling
indicative of the size of the HARQ payload from a network node.
13. The method of claim 1, further comprising: receiving signaling
indicative of whether to consider a presence of the at least one of
the SR or the P-CSI report in the selection of the PUCCH
format.
14. The method of claim 1, wherein the set of PUCCH formats
comprises a first PUCCH format associated with P-CSI reporting for
one CC and a second PUCCH format associated with P-CSI reporting
for two or more CCs.
15. The method of claim 1, wherein the uplink control message is
associated with a cell group among a plurality of cell groups.
16. A method of wireless communication, comprising: receiving a
configuration supporting transmission of a plurality of periodic
channel state information (P-CSI) reports during a same
transmission time interval (TTI), wherein the plurality of P-CSI
reports are associated with two or more of P-CSI reports for a
plurality of subframe sets of a channel state information (CSI)
process, P-CSI reports for a plurality of CSI processes of a
component carrier (CC), or P-CSI reports for a plurality of CCs of
a carrier aggregation (CA) configuration; determining that two or
more P-CSI reports are due for transmission during the TTI; and
transmitting at least one of the two or more P-CSI reports during
the TTI according to a prioritization rule, wherein the
prioritization rule is based at least in part on a payload capacity
of a physical uplink control channel (PUCCH) format or payload
sizes of the two or more P-CSI reports.
17. The method of claim 16, wherein the configuration supporting
transmission of the plurality of P-CSI reports comprises at least
one of a coordinated multipoint (CoMP) configuration, a CA
configuration with one or more PUCCH groups, a dual-connectivity
configuration, or an interference mitigation and traffic adaptation
(IMTA) configuration.
18. The method of claim 16, wherein the prioritization rule
comprises prioritizing by a CSI type, followed by a CSI process
identification (ID), followed by a CC index, followed by a subframe
set index.
19. The method of claim 16, wherein the CA configuration comprises
a configuration of more than five CCs.
20. A mobile device, comprising: a processor; memory in electronic
communication with the processor; and instructions stored in the
memory and operable, when executed by the processor, to cause the
mobile device to: detect a size of a hybrid automatic repeat
request (HARQ) payload for reporting, in a subframe, HARQ feedback
associated with transmissions on a plurality of component carriers
(CCs); determine that at least one of a scheduling request (SR), a
periodic channel state information (P-CSI) report, or a combination
thereof is to be included in the subframe; select a physical uplink
control channel (PUCCH) format from a set of PUCCH formats based at
least in part on a comparison of a size of an uplink control
message with a threshold, wherein the uplink control message
comprises the HARQ payload and a payload for at least one of the SR
or the P-CSI report; and transmit the uplink control message in the
subframe using the selected PUCCH format.
21. The mobile device of claim 20, wherein when the size of the
uplink control message is greater than the threshold, the
instructions to select the PUCCH format are operable to cause the
mobile device to select a PUCCH format having a greater capacity
than at least one other PUCCH format from the set of PUCCH
formats.
22. The mobile device of claim 20, wherein the instructions are
operable to cause the mobile device to: multiplex the HARQ payload
with P-CSI reports for two or more CCs configured for the UE,
wherein determining that at least one of an SR or a P-CSI report is
to be included in the subframe comprises identifying the P-CSI
reports for the two or more CCs configured for the UE.
23. The mobile device of claim 20, wherein the instructions are
operable to cause the mobile device to: receive signaling
indicative of the size of the HARQ payload from a network node.
24. The mobile device of claim 20, wherein the instructions are
operable to cause the mobile device to: receive signaling
indicative of whether to consider a presence of the at least one of
the SR or the P-CSI report in the selection of the PUCCH
format.
25. The mobile device of claim 20, wherein the uplink control
message is associated with a cell group among a plurality of cell
groups.
26. An mobile device for wireless communication, comprising: a
processor; memory in electronic communication with the processor;
and instructions stored in the memory and operable, when executed
by the processor, to cause the mobile device to: receive a
configuration supporting transmission of a plurality of periodic
channel state information (P-CSI) reports during a same
transmission time interval (TTI), wherein the plurality of P-CSI
reports are associated with two or more of P-CSI reports for a
plurality of subframe sets of a channel state information (CSI)
process, P-CSI reports for a plurality of CSI processes of a
component carrier (CC), or P-CSI reports for a plurality of CCs of
a carrier aggregation (CA) configuration; determine that two or
more P-CSI reports are due for transmission during the TTI; and
transmit at least one of the two or more P-CSI reports during the
TTI according to a prioritization rule, wherein the prioritization
rule is performed based at least in part on a payload capacity of a
physical uplink control channel (PUCCH) format or payload sizes of
the two or more P-CSI reports.
27. The mobile device of claim 26, wherein the configuration
supporting transmission of the plurality of P-CSI reports comprises
at least one of a coordinated multipoint (CoMP) configuration, a CA
configuration with one or more PUCCH groups, a dual-connectivity
configuration, or an interference mitigation and traffic adaptation
(IMTA) configuration.
28. The mobile device of claim 26, wherein the prioritization rule
comprises prioritizing a CSI type, followed by a CSI process
identification (ID), followed by a CC index, followed by a subframe
set index.
29. The mobile device of claim 20, wherein the set of PUCCH formats
comprises a first set of PUCCH formats associated with reporting
HARQ feedback for one CC, a second set of PUCCH formats associated
with reporting HARQ feedback for up to five CCs, or a third set of
PUCCH formats associated with reporting HARQ feedback for more than
five CCs.
30. The mobile device of claim 20, wherein the instructions to
determine that at least one of the SR or the P-CSI report is to be
included in the subframe are operable to cause the mobile device
to: determine to report a subset of P-CSI reports from a set of
P-CSI reports, wherein determining to report a subset of P-CSI
reports from a set of P-CSI reports comprises prioritizing based on
P-CSI report types, followed by prioritizing based on a CSI process
identification, followed by prioritizing based on a CC index,
followed by prioritizing based on a subframe set index.
Description
BACKGROUND
The following relates generally to wireless communication, and more
specifically to periodic channel state information (P-CSI)
reporting for enhanced carrier aggregation (eCA).
Wireless communications systems are widely deployed to provide
various types of communication content such as voice, video, packet
data, messaging, broadcast, and so on. These systems may be capable
of supporting communication with multiple users by sharing the
available system resources (e.g., time, frequency, and power).
Examples of such multiple-access systems include code division
multiple access (CDMA) systems, time division multiple access
(TDMA) systems, frequency division multiple access (FDMA) systems,
and orthogonal frequency division multiple access (OFDMA) systems,
(e.g., a Long Term Evolution (LTE) system). A wireless
multiple-access communications system may include a number of base
stations, each simultaneously supporting communication for multiple
communication devices, which may be otherwise known as user
equipment (UE).
A UE may send P-CSI reports to a base station to provide feedback
on channel conditions. The number of scheduled P-CSI reports may
increase in proportion to the number of different component
carriers (CCs) the UE and base station use for communication. If
the UE and the base station are communicating using a large number
of CCs (e.g., in an enhanced or evolved CA (eCA) configuration), a
large amount of information may be queued for uplink transmission.
In some cases, the uplink control channel may not provide
sufficient resources for transmission of the queued P-CSI reports
together with other uplink control information such as hybrid
automatic repeat request (HARQ) feedback.
SUMMARY
A user equipment (UE) may detect the size of a hybrid automatic
repeat request (HARQ) payload for a set of component carriers
(CCs). The UE may also determine that a scheduling request (SR) or
a periodic channel state information (P-CSI) report is present
(e.g., to be included in a TTI, to be included in a subframe, to be
transmitted in a subframe, to be included in an uplink (UL) control
message, to be included with HARQ feedback in a subframe, available
for transmission in a subframe, etc.). If the combined uplink
payload (e.g., the combined payload size of the HARQ and the SR or
P-CSI report) is above a threshold, the UE may select a physical
uplink control channel (PUCCH) format associated with, and that can
support feedback for, a large number of CCs. If the payload is
below the threshold, a format for a smaller number of CCs may be
selected. In some cases, the UE may receive a configuration of two
or more P-CSI reports during a subframe for a number of CCs of a
carrier aggregation (CA) configuration. The UE may then prioritize
the P-CSI reports due for transmission during a given subframe and
may transmit at least one and possibly two or more of the reports
according to the prioritization.
A method of wireless communication is described. The method may
include detecting a size of a HARQ payload for reporting, in a
subframe, HARQ feedback associated with transmissions on a
plurality of CCs, determining that at least one of a SR, a periodic
channel state information (P-CSI) report, or a combination thereof
is to be included in the subframe, selecting a PUCCH format from a
set of PUCCH formats based at least in part on a comparison of a
size of an uplink control message with a threshold, wherein the
uplink control message includes the HARQ payload and a payload for
at least one of the SR or the P-CSI report, and transmitting the
uplink control message in the subframe using the selected PUCCH
format.
A mobile device. The mobile device may include means for detecting
a size of a HARQ payload for reporting, in a subframe, HARQ
feedback associated with transmissions on a plurality of CCs, means
for determining that at least one of a SR or a periodic channel
state information (P-CSI) report, or a combination thereof is to be
included in the subframe, means for selecting a PUCCH format from a
set of PUCCH formats based at least in part on a comparison of a
size of an uplink control message with a threshold, wherein the
uplink control message includes the HARQ payload and a payload for
at least one of the SR or the P-CSI report, and means for
transmitting the uplink control message in the subframe using the
selected PUCCH format.
Another mobile device is described. The mobile device may include a
processor, memory in electronic communication with the processor,
and instructions stored in the memory and operable, when executed
by the processor, to cause the mobile device to detect a size of a
HARQ payload for reporting, in a subframe, HARQ feedback associated
with transmissions on a plurality of CCs, determine that at least
one of a SR or a periodic channel state information (P-CSI) report,
or a combination thereof is to be included in the subframe, select
a PUCCH format from a set of PUCCH formats based at least in part
on a comparison of a size of an uplink control message with a
threshold, wherein the uplink control message includes the HARQ
payload and a payload for at least one of the SR or the P-CSI
report, and transmit the uplink control message in the subframe
using the selected PUCCH format.
A non-transitory computer-readable medium storing code for wireless
communication is described. The code may include instructions
executable to detect a size of a HARQ payload for reporting, in a
subframe, HARQ feedback associated with transmissions on a
plurality of CCs, determine that at least one of a SR or a periodic
channel state information (P-CSI) report, or a combination thereof
is to be included in the subframe, select a PUCCH format from a set
of PUCCH formats based at least in part on a comparison of a size
of an uplink control message with a threshold, wherein the uplink
control message includes the HARQ payload and a payload for at
least one of the SR or the P-CSI report, and transmit the uplink
control message using the selected PUCCH format.
In some examples of the method, mobile devices, or non-transitory
computer-readable medium described herein, the set of PUCCH formats
may include a first PUCCH format associated with P-CSI reporting
for one CC and a second PUCCH associated with P-CSI reporting for
two or more CCs. In some examples the set of PUCCH formats may
include a first PUCCH format associated with reporting HARQ
feedback for one CC, a second PUCCH format associated with
reporting HARQ feedback for up to five CCs, and a third PUCCH
format associated with reporting HARQ feedback for more than five
CCs. Additionally or alternatively, some examples may include
steps, features, means, or instructions for selecting the set of
PUCCH formats based at least in part on a number of CCs in the
plurality of CCs, and determining whether a size of the payload for
the at least one of the SR or P-CSI report is included in the size
of the uplink control message for the comparison with the threshold
based at least in part on the selected set of PUCCH formats. In
some examples, when the size of the uplink control message is
greater than the threshold, the method, mobile devices, or
non-transitory computer-readable medium may include operations,
features, means, or instructions for selecting a PUCCH format
having a greater capacity than at least one other PUCCH format from
the set of PUCCH formats. In some examples the threshold may have a
size of 22 bits.
In some examples of the method, mobile devices, or non-transitory
computer-readable medium described herein, selecting the PUCCH
format may include steps, features, means or instructions for
selecting the third PUCCH format based at least in part on the
uplink control message size exceeding the threshold. Additionally
or alternatively, some examples may include steps, features, means,
or instructions for multiplexing the HARQ payload with P-CSI
reports for two or more CCs configured for the UE, and determining
that at least one of an SR or a P-CSI report is to be included in
the subframe may include identifying the P-CSI reports for the two
or more CCs configured for the UE.
In some examples of the method, mobile devices, or non-transitory
computer-readable medium described herein, the SR is determined to
be present and the uplink control message may include the HARQ
payload and a payload for the SR. Additionally or alternatively, in
some examples the SR and the P-CSI report are determined to be
present and the uplink control message may include the HARQ
payload, a payload for the SR, and a payload for the P-CSI.
In some examples of the method, mobile devices, or non-transitory
computer-readable medium described herein, the PUCCH format is
selected based at least in part on a scaled P-CSI report payload
size. In some examples the P-CSI report may include a report from
at least one P-CSI process from a plurality of P-CSI processes for
a CC configured for the UE, a report from a P-CSI process for at
least one P-CSI subframe set from a plurality of P-CSI subframe
sets for a CC configured for the UE, or a combination thereof.
Additionally or alternatively, in some examples determining that at
least one of the SR or the P-CSI report is to be included in the
subframe may include steps, features, means, or instructions for
determining to report a subset of P-CSI reports from a set of P-CSI
reports. In some examples determining to report a subset of P-CSI
reports from a set of P-CSI report types reports may include steps,
features, means, or instructions for prioritizing P-CSI reports
based on P-CSI report types, the prioritizing performed within a CC
configured for the UE, or across CCs configured for the UE, or a
combination thereof. In some examples determining to report a
subset of P-CSI reports from a set of P-CSI reports may include
steps, features, means, or instructions for prioritizing based on
P-CSI report types, followed by prioritizing based on a CSI process
identification, followed by prioritizing based on a CC index,
followed by prioritizing based on a subframe set index.
In some examples of the method, mobile devices, or non-transitory
computer-readable medium described herein, the set of P-CSI report
types includes P-CSI report types that support rank indicator (RI)
feedback or wideband precoding matrix indicator (PMI) feedback.
Additionally or alternatively, some examples may include steps,
features, means, or instructions for receiving signaling indicative
of the HARQ payload size from a network node.
Some examples of the method, mobile devices, or non-transitory
computer-readable medium described herein may further include
steps, features, means, or instructions for receiving signaling
indicative of whether to consider a presence of the at least one of
the SR or the P-CSI report in the selection of the PUCCH format.
Additionally or alternatively, in some examples the signaling
includes radio resource control (RRC) signaling. Some examples of
the method, mobile devices, or non-transitory computer-readable
medium may include steps, features, means, or instructions for
receiving RRC signaling indicative of the threshold.
In some examples of the method, mobile devices, or non-transitory
computer-readable medium described herein, the uplink control
message is associated with a cell group among a plurality of cell
groups.
Another method of wireless communication is described. The method
may include receiving a configuration supporting transmission of a
plurality of periodic channel state information (P-CSI) reports
during a same TTI, wherein the P-CSI reports are associated with
two or more of P-CSI reports for a plurality of subframe sets of a
CSI process, P-CSI reports for a plurality of CSI processes of a
CC, or P-CSI reports for a plurality of CCs of a CA configuration,
determining two or more P-CSI reports due for transmission during a
TTI, and transmitting at least one of the P-CSI reports during the
TTI according to a prioritization rule.
Another mobile device is described. The mobile device may include
means for receiving a configuration supporting transmission of a
plurality of periodic channel state information (P-CSI) reports
during a TTI, wherein the plurality of P-CSI reports are associated
with two or more of P-CSI reports for a plurality of subframe sets
of a CSI process, P-CSI reports for a plurality of CSI processes of
a CC, or P-CSI reports for a plurality of CCs of a CA
configuration, means for determining two or more P-CSI reports due
for transmission during a TTI, and means for transmitting at least
one of the P-CSI reports during the TTI according to a
prioritization rule.
Another mobile device is described. The mobile device may include a
processor, memory in electronic communication with the processor,
and instructions stored in the memory and operable, when executed
by the processor, to cause the mobile device to receive a
configuration supporting transmission of a plurality of periodic
channel state information (P-CSI) reports during a TTI, wherein the
plurality of P-CSI reports are associated with two or more of P-CSI
reports for a plurality of subframe sets of a CSI process, P-CSI
reports for a plurality of CSI processes of a CC, or P-CSI reports
for a plurality of CCs of a CA configuration, determine two or more
P-CSI reports due for transmission during a TTI, and transmit at
least one of the P-CSI reports during the TTI according to a
prioritization rule.
Another non-transitory computer-readable medium storing code for
wireless communication is described. The code may include
instructions executable to receive a configuration supporting
transmission of a plurality of periodic channel state information
(P-CSI) reports during a TTI, wherein the plurality of P-CSI
reports are associated with two or more of P-CSI reports for a
plurality of subframe sets of a CSI process, P-CSI reports for a
plurality of CSI processes of a CC, or P-CSI reports for a
plurality of CCs of a CA configuration, determine two or more P-CSI
reports due for transmission during a TTI, and transmit at least
one of the P-CSI reports during the TTI according to a
prioritization rule.
In some examples of the method, mobile devices, or non-transitory
computer-readable medium described herein, the prioritization rule
is performed based at least in part on a payload capacity or
payload sizes of the two or more P-CSI reports. Additionally or
alternatively, in some examples the payload capacity is based at
least in part on a PUCCH format.
In some examples of the method, mobile devices, or non-transitory
computer-readable medium described herein, the configuration
supporting transmission of the plurality of P-CSI reports includes
at least one of a coordinated multipoint (CoMP) configuration, a CA
configuration with one or more PUCCH groups, a dual-connectivity
configuration, or an interference mitigation and traffic adaptation
(IMTA) configuration. Additionally or alternatively, in some
examples the prioritization rule includes prioritizing a CSI type,
followed by a CSI process identification (ID), followed by a CC
index, followed by a subframe set index.
In some examples of the method, mobile devices, or non-transitory
computer-readable medium described herein, the CA configuration
includes a configuration of more than five CCs.
BRIEF DESCRIPTION OF THE DRAWINGS
Aspects of the disclosure are described in reference to the
following figures:
FIG. 1 illustrates an exemplary wireless communications system that
supports periodic channel state information (P-CSI) reporting for
enhanced carrier aggregation (eCA) in accordance with various
aspects of the present disclosure;
FIG. 2 illustrates an exemplary wireless communications system that
supports aspects of P-CSI reporting for eCA in accordance with
various aspects of the present disclosure;
FIG. 3 illustrates an exemplary multi-CSI feedback process that
supports aspects of P-CSI reporting for eCA in accordance with
various aspects of the present disclosure;
FIG. 4 illustrates an exemplary process flow that supports aspects
of P-CSI reporting for eCA in accordance with various aspects of
the present disclosure;
FIGS. 5-7 show block diagrams of a wireless device that supports
aspects of P-CSI reporting for eCA in accordance with various
aspects of the present disclosure;
FIG. 8 illustrates a block diagram of a system, including a user
equipment (UE), that supports aspects of P-CSI reporting for eCA in
accordance with various aspects of the present disclosure; and
FIGS. 9-13 illustrate methods for P-CSI reporting for eCA in
accordance with various aspects of the present disclosure.
DETAILED DESCRIPTION
In some wireless systems, a user equipment (UE) can be configured
with a number component carriers (CC) for carrier aggregation (CA)
operation. The UE can be configured to report channel conditions
for each CC with periodic CSI (P-CSI) reports. The size of uplink
control information transmissions may increase as the number of CCs
in the CA configuration increases. Thus, different physical uplink
control channel (PUCCH) formats may be used depending on the number
of CCs. As disclosed herein, the UE may select a particular PUCCH
format for an uplink control message based on the relative
importance placed on P-CSI reporting. Techniques for supporting
multiple P-CSI reports for a single CC, such as in support of
certain operations in an eCA configuration, are also described.
In some cases when a UE is configured to provide P-CSI feedback for
multiple CCs in an uplink control message (e.g., in a TTI, in a
subframe, etc.), the UE may be subject reporting limits such that
only a subset of the CSI reports may be reported. For example, the
UE may be limited to a single P-CSI report for each CC. Thus, if
there are two or more P-CSI reports due for the same CC, one P-CSI
report may be reported while all others are dropped. A UE may apply
prioritization rules across the CCs, and within each CC, based on
the capacity of the PUCCH format in use (e.g., CSI type first,
followed by a CSI process ID, followed by CC index, followed by
subframe set ID). In other cases, a UE may be configured to
prioritize P-CSI reporting, and may select a PUCCH format likely to
support (e.g., having sufficient communication resource capacity
for) P-CSI reporting in addition to other uplink control
information.
In some wireless systems, a UE may be limited to a certain number
of CCs (e.g., 5 CCs). In other systems, a UE may be configured for
a larger number of CCs (e.g., up to 32 CCs in an enhanced carrier
aggregation (eCA) configuration). ECA configurations may also
support PUCCH transmissions on both primary and secondary CCs for
UEs supporting uplink CA. Some sets of PUCCH formats may support CA
while others may support eCA.
In response to different uplink control information combinations,
different PUCCH formats may be selected (e.g., for a TTI or
subframe used to transmit an associated uplink control message). In
some cases, the selection of the possible set of PUCCH formats may
be based on a HARQ condition determined by the UE. For non-CA
scheduling, non-CA PUCCH formats may be selected. For CA
scheduling, CA PUCCH formats may be selected. As discussed herein,
non-CA PUCCH formats may refer to those PUCCH formats that support
fewer bits of uplink control information (UCI) and thus may not
support (e.g., may have insufficient communication resource
capacity for) UCI transmission for CA configurations. CA PUCCH
formats may refer to those PUCCH formats that support a larger
number of bits for UCI and therefore support UCI transmission for
CA configurations.
If P-CSI is not involved in a PUCCH format determination, a UE may
determine a PUCCH format to use based on hybrid automatic repeat
request (HARQ) acknowledgement/negative acknowledgement (ACK/NACK)
and then may determine how to multiplex P-CSI. In cases in which
P-CSI can be multiplexed with HARQ ACK/NACK, P-CSI may be used to
determine which PUCCH format should be used. In some examples, a
scheduling request (SR) may also be involved in PUCCH format
determination.
Aspects of the disclosure introduced above are described below in
the context of a wireless communication system. Specific examples
are then described for selecting which PUCCH format to use from a
set of PUCCH formats, and transmitting an uplink control message
using the selected PUCCH format. Examples are also described for
determining the presence of a collision of P-CSI reports during a
TTI, and transmitting one or more P-CSI reports based on a
prioritization rule during the TTI. These and other aspects of the
disclosure are further illustrated by and described with reference
to apparatus diagrams, system diagrams, and flowcharts that relate
to P-CSI in eCA.
FIG. 1 illustrates an example of a wireless communications system
100 that supports P-CSI reporting for eCA in accordance with
various aspects of the present disclosure. The wireless
communications system 100 includes base stations 105, user
equipment (UEs) 115, and a core network 130. In some examples, the
wireless communications system 100 may be a Long Term Evolution
(LTE)/LTE-Advanced (LTE-A) network. Wireless communications system
100 may be configured to support a large number of CCs for
communications between UEs 115 and base stations 105. For example,
UEs 115 may be configured to support prioritization of P-CSI
reports and to transmit PUCCH using an expanded set of PUCCH
formats.
Base stations 105 may wirelessly communicate with UEs 115 via one
or more base station antennas. Each base station 105 may provide
communication coverage for a respective geographic coverage area
110. Communication links 125 shown in wireless communications
system 100 may include uplink (UL) transmissions from a UE 115 to a
base station 105, or downlink (DL) transmissions, from a base
station 105 to a UE 115. UEs 115 may be dispersed throughout the
wireless communications system 100, and each UE 115 may be
stationary or mobile. A UE 115 may also be referred to as a mobile
station, a subscriber station, a mobile unit, a subscriber unit, a
wireless unit, a remote unit, a mobile device, a wireless device, a
wireless communications device, a remote device, a mobile
subscriber station, an access terminal, a mobile terminal, a
wireless terminal, a remote terminal, a handset, a user agent, a
mobile client, a client, or some other suitable terminology. A UE
115 may also be a cellular phone, a personal digital assistant
(PDA), a wireless modem, a wireless communication device, a
handheld device, a tablet computer, a laptop computer, a cordless
phone, a personal electronic device, a handheld device, a personal
computer, a wireless local loop (WLL) station, an Internet of
things (IoT) device, an Internet of Everything (IoE) device, a
machine type communication (MTC) device, an appliance, an
automobile, or the like.
Base stations 105 may communicate with the core network 130 and
with one another. For example, base stations 105 may interface with
the core network 130 through backhaul links 132 (e.g., S1, etc.).
Base stations 105 may communicate with one another over backhaul
links 134 (e.g., X2, etc.) either directly or indirectly (e.g.,
through core network 130). Base stations 105 may perform radio
configuration and scheduling for communication with UEs 115, or may
operate under the control of a base station controller (not shown).
In some examples, base stations 105 may be macro cells, small
cells, hot spots, or the like. Base stations 105 may also be
referred to as eNodeBs (eNBs) 105.
A UE 115 may be configured to collaboratively communicate with
multiple base stations 105 through, for example, Multiple Input
Multiple Output (MIMO), Coordinated Multi-Point (CoMP), or other
schemes. MIMO techniques may use multiple antennas on the base
stations or multiple antennas on the UE to take advantage of
multipath environments to transmit multiple data streams. CoMP
includes techniques for dynamic coordination of transmission and
reception by a number of eNBs to improve overall transmission
quality for UEs 115 as well as increasing network and spectrum
utilization. CoMP configurations may affect a P-CSI reporting
(e.g., a CSI process for P-CSI) of a UE 115, and thus may affect
the PUCCH format selection or P-CSI report prioritization of the UE
115.
The wireless communications system 100 may also employ Interference
Management and Traffic Adaptation (IMTA) or enhanced IMTA (eIMTA)
techniques. IMTA/eIMTA may include techniques for flexible
resources of a time-division duplexing (TDD) carrier based on
traffic load considerations. For example, IMTA may involve
transmitting DL data in UL frames when DL traffic is heavy, or
reserving flexible subframes that may be used for either UL or DL.
IMTA may also involve techniques for coordinated power control and
interstation scheduling. IMTA configurations may also affect a
P-CSI reporting (e.g., a subframe set for P-CSI) of a UE 115, and
thus may affect a PUCCH format selection or P-CSI report
prioritization of the UE 115.
A communication link 125 may include one or more frequency ranges
organized into carriers. A carrier may also be referred to as a CC,
a layer, a channel, etc. The term "component carrier" may refer to
each of the multiple carriers utilized by a UE in carrier
aggregation (CA) operation, and may be distinct from other portions
of system bandwidth. For instance, a CC may be a relatively
narrow-bandwidth carrier that supports being utilized independently
or in combination with other CCs. Each CC may provide the same
capabilities as an isolated carrier based on release 8 or release 9
of the LTE standard.
Multiple CCs may be aggregated or utilized concurrently to provide
some UEs 115 with greater bandwidth, which may support higher data
rates. Thus, individual CCs may be backwards compatible with legacy
UEs 115 (e.g., UEs 115 implementing LTE release 8 or release 9),
while other UEs 115 (e.g., UEs 115 implementing post-release 8/9
LTE versions), may be configured with multiple CCs in a
multi-carrier mode. A carrier used for downlink (DL) may be
referred to as a DL CC, and a carrier used for uplink (UL) may be
referred to as an UL CC. A UE 115 may be configured with multiple
DL CCs and one or more UL CCs for carrier aggregation. Each carrier
may be used to transmit control information (e.g., reference
signals, control channels, etc.), overhead information, data, etc.
A UE 115 may communicate with a single base station 105 utilizing
multiple carriers, and may also communicate with multiple base
stations simultaneously on different carriers.
In some cases, wireless communications system 100 may utilize one
or more enhanced component carriers (eCCs). An eCC may be
characterized by one or more features including: flexible
bandwidth, different transmission time interval (TTIs), and
modified control channel configuration. In some cases, an eCC may
be associated with a CA configuration or a dual connectivity
configuration (e.g., when multiple serving cells have a suboptimal
backhaul link). An eCC may also be configured for use in an
unlicensed radio frequency spectrum band or a shared radio
frequency spectrum band (e.g., where more than one operator is
licensed to use the radio frequency spectrum band). An eCC
characterized by flexible bandwidth may include one or more
bandwidth segments that may be utilized by UEs 115 that do not or
are not capable of monitoring the whole bandwidth or are otherwise
configured to use a limited bandwidth (e.g., to conserve
power).
Each cell of a base station 105 may include an UL CC and a DL CC.
The geographic coverage area 110 of each serving cell for a base
station 105 may be different (e.g., CCs on different frequency
bands may experience different path loss). In some examples, one
carrier is designated as the primary carrier, or primary component
carrier (PCC), for a UE 115, which may be served by a primary cell
(PCell). Primary cells may be semi-statically configured by higher
layers (e.g., radio resource control (RRC) layer, etc.) on a per-UE
basis. Certain UCI (e.g., ACK/NACK), channel quality indicator
(CQI), and scheduling information transmitted on physical uplink
control channel (PUCCH) may be carried by the primary cell.
Additional carriers may be designated as secondary carriers, or
secondary component carriers (SCC), which may be served by
secondary cells (SCells). Secondary cells may also be
semi-statically configured on a per-UE basis. In some cases,
secondary cells may not include or may not be configured to
transmit the same control information as the primary cell. In other
cases, one or more secondary cell (SCells) may be designated to
carry physical uplink control channel (PUCCH), and the SCells may
be organized into PUCCH groups based on which CC is used to carry
the associated UL control information. Some wireless networks may
utilize enhanced CA operations based on a large number of carriers
(e.g., between 5 and 32 carriers), operation in an unlicensed radio
frequency spectrum band, or use of enhanced CCs. Operation with a
large number of carriers may be characterized by modified control
configurations such as modified PUCCH procedures to report CSI
information.
PUCCH may be used for UL HARQ ACK/NACK, SRs, CQI, and other UL
control information. A PUCCH may be mapped to a control channel
defined by a code and two consecutive resource blocks. UL control
signaling may depend on the presence of timing synchronization for
a cell. PUCCH resources for scheduling request (SR) and channel
quality indicator (CQI) reporting may be assigned or revoked
through radio resource control (RRC) signaling. In some cases,
resources for SR may be assigned after acquiring synchronization
through a random access channel (RACH) procedure. In other cases,
an SR may not be assigned to a UE 115 through the RACH (i.e.,
synchronized UEs 115 may or may not have a dedicated SR channel).
PUCCH resources for SR and CQI may be lost when the UE 115 is no
longer synchronized. In some cases, PUCCH formats may be selected
based on the size of an uplink control payload which may include
HARQ, CSI, and SR information. If a large number of CCs are
configured, expanded PUCCH formats may be used to accommodate large
PUCCH payloads.
HARQ may be a method of ensuring that data is received correctly
over a communication link 125. HARQ may include a combination of
error detection (e.g., using a cyclic redundancy check (CRC)),
forward error correction (FEC), and retransmission (e.g., automatic
repeat request (ARQ)). HARQ may improve throughput at the medium
access control (MAC) layer in poor radio conditions (e.g., poor
signal-to-noise ratio conditions). In Incremental Redundancy HARQ,
incorrectly received data may be stored in a buffer and combined
with subsequent transmissions to improve the overall likelihood of
successfully decoding the data. In some cases, redundancy bits are
added to each message prior to transmission. This may be especially
useful in poor radio conditions. In other cases, redundancy bits
are not added to each transmission, but are retransmitted after the
transmitter of the original message receives a NACK indicating a
failed attempt to decode the information. The chain of
transmission, response and retransmission may be referred to as a
HARQ process. In some cases, a limited number of HARQ processes may
be used for a given communication link 125.
A base station 105 may insert periodic pilot symbols such as
cell-specific reference signals (CRS) to aid UEs 115 in channel
estimation and coherent demodulation. CRS may include one of 504
different cell identities. They may be modulated using quadrature
phase shift keying (QPSK) and power boosted (e.g., transmitted at 6
dB higher than the surrounding data elements) to make them more
resilient to noise and interference. CRS may be embedded in 4 to 16
resource elements in each resource block based on the number of
antenna ports or layers (up to 4) of the receiving UEs 115. In
addition to CRS, which may be utilized by all UEs 115 in the
geographic coverage area 110 of the base station 105, demodulation
reference signal (DMRS) may be directed toward specific UEs 115 and
may be transmitted only on resource blocks assigned to those
respective UEs 115. In some cases, additional reference signals
known as channel state information reference signals (CSI-RS) may
be included to aid in generating CSI. On the UL, a UE 115 may
transmit a combination of periodic sounding reference signal (SRS)
and UL DMRS for link adaptation and demodulation, respectively.
A base station 105 may gather channel condition information from a
UE 115 based on the pilot symbols in order to efficiently configure
and schedule the channel. This information may be sent from the UE
115 in the form of a channel state report. A channel state report
may contain a rank indicator (RI) requesting a number of layers to
be used for DL transmissions (e.g., based on the antenna ports of
the UE 115), a precoding matrix indicator (PMI) indicating a
preference for which precoder matrix should be used (e.g., based on
the number of layers), and a CQI representing the highest
modulation and coding scheme (MCS) that may be used. CQI may be
calculated by a UE 115 after receiving predetermined pilot symbols
such as CRS or CSI-RS. RI and PMI may be excluded if the UE 115
does not support spatial multiplexing (or is not operating in a
mode that supports spatial multiplexing). The types of information
included in the report determines a reporting type. Channel state
reports may be periodic or aperiodic. That is, a base station 105
may configure a UE 115 to send periodic reports at regular
intervals, and may also request additional reports as needed.
Aperiodic reports may include wideband reports indicating the
channel quality across an entire cell bandwidth, UE-selected
reports indicating a subset of the best subbands, or configured
reports in which the subbands reported are selected by the base
station 105. In some cases, a UE 115 may prioritize some P-CSI
reports over others to ensure that higher priority reports are
transmitted to a base station 105 when multiple P-CSI reports are
scheduled for the same subframe.
Some examples of possible P-CSI report types include: a Type 1
report, which may support CQI feedback; a Type 1a report, which may
support subband CQI and second PMI feedback, Type 2, Type 2b, and
Type 2c reports, which may support wideband CQI and PMI feedback; a
Type 2a report, which may support wideband PMI feedback; a Type 3
report, which may support RI feedback; a Type 4 report, which may
support wideband CQI; a Type 5 report, which may support RI and
wideband PMI feedback; and a Type 6 report, which may support RI
and precoder type indication (PTI) feedback.
In some cases, a UE 115 may detect the size of a HARQ payload for
reporting HARQ feedback associated with transmissions on a set of
CCs. The UE 115 may also determine that a SR or a P-CSI report may
be present (e.g., to be included in a TTI, to be included in a
subframe, to be transmitted in a subframe, to be included in an
uplink (UL) control message, to be included with HARQ feedback in a
subframe, available for transmission in a subframe, etc.). If the
combined uplink payload is above a threshold, the UE 115 may select
a PUCCH format associated with a large number of CCs. If the
payload is below the threshold, a format for a smaller number of
CCs may be selected. In some cases, the UE 115 may receive a
configuration of two or more P-CSI reports during a subframe for a
number of CCs of a CA configuration. The UE 115 may then prioritize
the P-CSI reports due for transmission during a given subframe and
may transmit at least one of the reports (e.g., at least a subset
of the configured P-CSI reports) according to the
prioritization.
FIG. 2 illustrates an example of a wireless communications system
200 that supports P-CSI reporting in eCA in accordance with various
aspects of the present disclosure. Wireless communications system
200 may include a UE 115-a and base station 105-a, which may be
examples of a UE 115 and base station 105 described with reference
to FIG. 1. Wireless communications system 200 may be configured to
support a large number of CCs 220 for communications between UE
115-a and base station 105-a. For example, UE 115-a may be
configured to support prioritization of P-CSI reports and to
transmit PUCCH using an expanded set of PUCCH formats.
Although some examples are described with respect to LTE systems,
the methods and mobile devices described herein may be extended to
other wireless systems. For example, embodiments of the present
disclosure may be extended or modified to be used with WiMAX, UMB,
or other 3G or 4G wireless systems that may or may not support
CA.
In some wireless systems, a UE 115 may be limited to a certain
number of CCs (e.g., 5 CCs). In other systems, a UE 115 may be
configured for a larger number of CCs (e.g., up to 32 CCs) in an
enhanced carrier aggregation (eCA) configuration. ECA
configurations may also support PUCCH transmissions on both primary
and secondary CCs for UEs supporting uplink CA, as mentioned above.
UE 115-a may represent a UE 115 configured with a large number of
CCs (e.g., more than 5).
UE 115-a may be configured to report channel conditions for each CC
via P-CSI transmissions with a certain periodicity. In some
examples when a UE 115-a is configured to provide P-CSI feedback
for multiple CCs in a subframe, it may be subject reporting limits.
If there are two or more P-CSI reports due for the same CC, a
subset of the P-CSI reports (e.g., one P-CSI report) from a set of
P-CSI reports may be reported while others are dropped. In some
examples different PUCCH formats may be selected in response to
different uplink control information combinations. For non-CA
scheduling, non-CA PUCCH formats may be selected. For CA
scheduling, CA PUCCH formats may be selected. If P-CSI is not
involved in a selection, UE 115-a may determine a PUCCH format
based on HARQ alone, and may then multiplex P-CSI with a HARQ
payload. If P-CSI is involved in a selection, the P-CSI may be
multiplexed with the HARQ payload prior to comparison to the
threshold. SR may also be involved in PUCCH format
determination.
In some cases, one CC may be configured as the PCC for UE 115-a. In
some examples, the PCC may be the only CC that carries PUCCH and a
common search space for UE 115-a. In some wireless systems, PUCCH
may be enabled on two CCs in CA for UE 115-a. In such cases, in
addition to the PCC, one or more secondary cells may carry PUCCH.
For example, this capability may be utilized for dual-connectivity
and PUCCH load balancing. In dual connectivity, base station 105-a
may not have an ideal backhaul with other base station 105 (not
shown) supporting CCs for UE 115-a. Tight coordination between the
cells may not be possible due to limited backhaul capacity and
non-negligible backhaul latency (e.g., tens of milliseconds). In
dual-connectivity, cells may be partitioned into two groups, the
primary cell group (PCG) and the secondary cell group (SCG). Each
group may have one or more cells in carrier aggregation. Each group
may also have a single cell carrying PUCCH, where the PCell in PCG
carries PUCCH for the PCG and a primary SCell (PSCell) in the SCG
carries PUCCH for the SCG. Additionally, a common search space may
be monitored in the SCG by UE 115-a. In some cases, uplink control
information is separately conveyed to each group using the PUCCH in
each group.
In some examples, UE 115-a may be configured with P-CSI
transmission with a certain periodicity and subframe offset (e.g.,
a number of subframes between a DL subframe received from a base
station 105 and a responsive P-CSI report by the UE 115-a). P-CSI
configuration may be separate for different CCs in CA, each CSI
process if there are more than one CSI processes in CC, and each
subframe set if a CSI process has more than one subframe sets. In
some cases, there may be two or more CSI types for a CC due in the
subframe and, in some cases, only a subset (e.g., one type) can be
transmitted. Furthermore, if two or more CSI reports across CCs are
due in the subframe, only a subset (e.g., one CC's P-CSI report)
may be transmitted while other reports in collision may be dropped.
In various examples, determining to report a subset of P-CSI
reports may include prioritizing P-CSI reports based on P-CSI
report types, which may include a prioritization within a CC
configured for the UE 115-a, or across CCs configured for the UE
115-a, or a combination thereof. Additionally or alternatively,
P-CSI reports may include a report from at least one P-CSI process
from a plurality of P-CSI processes for a CC configured for the UE
115-a, a report from a P-CSI process for at least one P-CSI
subframe set from a plurality of P-CSI subframe sets for a CC
configured for the UE 115-a, or a combination thereof. In some
cases, P-CSI reports may be transmitted along with HARQ ACK/NACK
using, for example, PUCCH format 2/2a/2b (e.g., if a PCell is
scheduled in the primary group, or if the PUCCH enabled cell is
scheduled in the secondary group) and PUCCH format 3 under CA and
P-CSI. In some cases P-CSI reports can also be transmitted along
with HARQ ACK/NACK, if P-CSI and HARQ ACK/NACK are jointly coded
and mapped.
In some cases, P-CSI prioritization rules may include CSI type
first (e.g., within the same cell, types 3/5/6 first followed by
types 1/1a/2/2a/2b/2c/4; and across CCs, types 3/5/6/2a first
followed by types 2/2b/2c/4 followed by types 1/1a) followed by a
tie-breaker. In some examples, the tie-breaker may include CSI
process ID first (e.g., lower CSI process may correspond to higher
priority), followed by CC index (e.g., lower CC index may
correspond to higher priority), followed by subframe set index
(e.g., lower P-CSI subframe set index may correspond to higher
priority).
CA configurations may develop physical layer specifications for
PUCCH on SCells based on the possible mechanisms to enable carrier
aggregation of up to 32 CCs for DL and UL communication. For
example, some physical layer specifications may include DL control
signaling for up to 32 CCs including both self-scheduling and
cross-carrier scheduling, and UL control signaling for up to 32
CCs. In some cases, it may be appropriate to support UCI feedback
on PUCCH for up to 32 DL carriers, where the UCI signaling format
may support UCI feedback for up to 32 DL carriers.
For PUCCH configuration and P-CSI reporting on PUCCH, it may be
appropriate use techniques to reduce probability of dropping P-CSI,
such as multiplexing of P-CSI reports corresponding to multiple
serving cells in a subframe, and multiplexing of P-CSI reports
corresponding to multiple serving cells with HARQ ACK/NACK feedback
in a subframe. Additionally, UE 115-a may dynamically determine the
HARQ codebook size and the PUCCH format. In some cases, this may be
different from CA HARQ codebook size determination mechanisms based
on semi-static configuration of number of CCs in CA in a PUCCH cell
group and the DL transmission modes of each CC. Furthermore, it may
be appropriate to ensure understanding between base station 105-a
and UE 115-a regarding the HARQ codebook and the PUCCH format.
Wireless communications system 200 may support multi-CSI-process,
P-CSI configuration, or multi-subframe-set P-CSI configuration.
PUCCH format for HARQ feedback may also be subject to dynamic
adaptation. In some examples, at least one new PUCCH format may be
used for a large number of scheduled CCs, PUCCH format 3 may be
used when the number of scheduled CCs is small and PUCCH format
1a/1b/2/2a/2b may be used when the number of scheduled CCs is very
small (e.g., only a PCell is scheduled in the primary group, or
only a PUCCH enabled SCell is scheduled in the secondary
group).
If UE 115-a is configured to provide P-CSI for multiple CCs in a
subframe, UE 115-a may be limited to having a single P-CSI report
for each CC. In some examples, there may be two or more P-CSI
reports due within a CC (e.g., from different CSI processes,
different subframe sets, etc.). One P-CSI report may be reported
while others may be dropped. In these cases, prioritization rules
may apply (e.g., CSI type first, followed by CSI process ID,
followed by subframe set index). In other cases, UE 115-a may have
more than one P-CSI report for at least one CC. In such cases, UE
115-a may be subject to prioritization rules across the CCs or
within the CC, and may be based on the capacity of the PUCCH format
in use (e.g., CSI type first, followed by CSI process ID, followed
by CC index, followed by subframe set ID).
For example, there may be a case where 3 CCs of similar CSI type
may be due in the same subframe: CC1-CSI process ID 1 and subframe
set 1, CSI process ID 2, CC2-CSI process 3 and CC3-CSI process ID
1. In such cases, the priority will be: CC1-CSI process ID 1 and
subframe set 1, followed by CC3: CSI process ID 1, followed by
CC1-CSI process ID 2, followed by CC2-CSI process 3. In some cases
it may be appropriate to extend a multi P-CSI report to a multi-CSI
process/multi-subframe independent of a multi-CC P-CSI report. Even
if UE 115-a is not configured with CA (e.g., a non-CA operation),
UE 115-a may be configured to report
multi-CSI-process/multi-subframe-set P-CSI.
In response to different uplink control payload combinations (e.g.,
based on a comparison with a size threshold), different PUCCH
formats may be selected. The selection of the possible set of PUCCH
formats may be based on a HARQ condition determined by UE 115-a. In
some examples, HARQ may be detected for only non-CA scheduling, and
non-CA PUCCH formats may be selected (e.g., 1/1a/1b/2/2a/2b). In
other examples, HARQ may be detected to have CA scheduling involved
(e.g., a physical downlink shared channel (PDSCH) transmission may
be detected on a SCell) and CA PUCCH format 3 or PUCCH format 1b,
with channel selection, may be selected. Furthermore, if P-CSI can
be multiplexed with HARQ ACK/NACK, P-CSI may or may not be used to
determine which format to use (e.g., PUCCH format 3 or PUCCH format
2/2a/2b). In systems with up to 32 CCs configured, PUCCH format 3
and PUCCH format 2/2a/2b may carry at most one CC's P-CSI; or one
or more new PUCCH formats (e.g., PUCCH format 4 or 5) can carry
more than 1 CC's P-CSI. When P-CSI is due in a subframe along with
HARQ ACK/NACK, it may also be appropriate to determine if P-CSI
should be involved in PUCCH format selection.
In some cases, P-CSI may not be involved in PUCCH format selection.
In such cases, UE 115-a may determine a PUCCH format to use based
on HARQ ACK/NACK and may determine how to multiplex P-CSI. In other
cases, SR may be involved in PUCCH format determination. For
example, if HARQ payload is greater than 64 bits, an expanded PUCCH
format (e.g., format 5) may be used and multi-CC P-CSI may be
multiplexed; if HARQ payload is greater than 21 bits, PUCCH format
4 may be used and multi-CC P-CSI may be multiplexed; if HARQ
payload is associated with CA scheduling (e.g., at least one SCC is
scheduled), PUCCH format 3 may be used, and at most one CC's P-CSI
may be multiplexed; and if a HARQ payload corresponds to a non-CA
case, PUCCH format 2/2a/2b may be used to multiplex HARQ and P-CSI
bits. In some cases, this may allow for more efficient HARQ
operation. In the above example, if SR is present (e.g., to be
included in a TTI, to be included in a subframe, etc.), SR may be
counted along with HARQ payload against the corresponding
thresholds in determining the respective PUCCH format to use.
If P-CSI is involved in PUCCH format selection, UE 115-a may
determine a PUCCH format to use based on HARQ ACK/NACK and P-CSI.
SR may also be involved in PUCCH format determination. For example,
if the collective number of HARQ bits, SR bits and P-CSI bits
payload is greater than 64 bits, PUCCH format 5 may be used and
multi-CC P-CSI may be multiplexed; if the collective number of HARQ
bits, SR bits and P-CSI bits payload is greater than 22 bits, PUCCH
format 5 may be used and multi-CC P-CSI may be multiplexed; if HARQ
payload is associated with CA scheduling (e.g., at least one SCC is
scheduled), PUCCH format 3 may be used and at most one CC's P-CSI
may be multiplexed; and if a HARQ payload corresponds to a non-CA
case, PUCCH format 2/2a/2b may be used to multiplex HARQ and P-CSI
(e.g., if SR is not present). In some cases, this may allow for
more efficient P-CSI feedback. Thus, UE 115-a may be configured to
support both cases where P-CSI may or may not be involved in PUCCH
format selection.
FIG. 3 illustrates an example of a multi-CSI feedback process 300
for P-CSI reporting for eCA in accordance with various aspects of
the present disclosure. The multi-CSI feedback process 300 may
include a UE 115-b and base station (BS) 105-b, which may be
examples of a UE 115 and base station 105 described with reference
to FIGS. 1-2.
Multi-CSI feedback process 300 may illustrate aspects of
implementing a multi-CSI feedback process in a wireless
communication system between base station 105-b and UE 115-b. The
method of wireless communication may include receiving a
configuration supporting transmission of multiple P-CSI reports
during a TTI (e.g., a subframe). The P-CSI reports may be
associated with two or more P-CSI reports for multiple subframe
sets of a CSI process, P-CSI reports for multiple CSI processes of
a CC, or P-CSI reports for multiple CCs of a CA configuration.
At 305, base station 105-b may transmit a number of pilot signals
to UE 115-b for channel estimation. In some examples base station
105-b may also send configuration information to UE 115-b. The
configuration may support transmission of the multiple P-CSI
reports, and may include at least one of a CoMP configuration, a CA
configuration with one or more PUCCH groups, a dual-connectivity
configuration or an IMTA configuration. In some cases, the CA
configuration may include a configuration of more than five
CCs.
At 310, UE 115-b may determine two or more P-CSI reports due for
transmission during a TTI. At 315 UE 115-b may prioritize the P-CSI
reports according to a prioritization rule. The prioritization rule
may be based on a payload capacity or payload sizes of the two or
more P-CSI reports. In some cases, the payload capacity may be
based on a PUCCH format. For example, the prioritization rules may
include CSI type first, followed by a CSI process ID, followed by a
CC index, followed by a subframe set index. In various examples,
prioritization may be performed within a CC, or across CCs, or a
combination thereof.
At 320 UE 115-b may drop one or more non-prioritized P-CSI reports
and at 325, UE 115-b may transmit (e.g., in an uplink control
message) at least one of the P-CSI reports during the TTI according
to the prioritization rule.
FIG. 4 illustrates an example of a process flow 400 for P-CSI
reporting for eCA in accordance with various aspects of the present
disclosure. Process flow 400 may include a UE 115-c and base
station 105-c, which may be examples of a UE 115 and base station
105 described with reference to FIGS. 1-3. Process flow 400 may
illustrate signaling and operations for determining which PUCCH
format to use in a wireless communication system between base
station 105-c and 115-c. Changes, adaptations and modifications may
be made without departing from the scope of the disclosure.
At 405, base station 105-c may transmit one or more DL signals to
UE 115-c. The DL signals may be associated with one or more CCs and
with one or more HARQ processes. Base station 105-c may transmit
one or more pilot signals to UE 115-c for channel estimation. Thus,
UE 115-c may identify uplink control information such as HARQ
feedback and CSI based on the one or more DL signals.
At 410, UE 115-c may determine the size of a HARQ payload or the
overall uplink control information payload for the configured CCs,
and a CA configuration. In some cases, UE 115-c may receive
signaling indicative of the size of the HARQ payload from base
station 105-c.
At 415, UE 115-c may identify that at least one of a SR or a P-CSI
report is present (e.g., to be included in a TTI, to be included in
a subframe, available for transmission with the HARQ feedback in
the subframe, etc.) for an uplink control message. In some
examples, UE 115-c may be configured to multiplex the HARQ payload
with P-CSI reports for two or more CCs configured for the UE 115-c,
where UE 115-c may identify that at least one of an SR or a P-CSI
report is present by identifying the P-CSI reports for the two or
more CCs configured for the UE 115-c. UE 115-c may also identify
that at least one of an SR or a P-CSI report is present by
determining whether a P-CSI report type or a subset of P-CSI report
types of a set of P-CSI report types is present. In some examples,
the set of P-CSI report types may at least include P-CSI report
types that support RI feedback or wideband PMI feedback. The uplink
control message may be associated with a cell group among multiple
cell groups.
At 420, UE 115-c may select a PUCCH format group which may, for
example, be a first set of PUCCH formats associated with reporting
HARQ feedback for one CC, a second set of PUCCH formats associated
with reporting HARQ feedback for up to five CCs, or a third set of
PUCCH formats associated with reporting HARQ feedback for more than
five CCs. The PUCCH format group may be selected based on a number
of CCs in the multiple scheduled CCs. UE 115-c may also determine
whether a size of the payload for the at least one of the SR or
P-CSI report is included in the size of the uplink control message
for the comparison with the threshold based on the selected PUCCH
format group (e.g., a set of PUCCH formats).
At 425, UE 115-c may select a PUCCH format from a PUCCH format
group based on a comparison of a size of an uplink control message
with a threshold, where the uplink control message may include the
HARQ payload and a payload for at least one of the SR or the P-CSI
report. UE 115-c may select a PUCCH format having a greater
capacity than another PUCCH format based on the size of the uplink
control message exceeding the threshold. In some cases, the PUCCH
format may be selected based on a scaled P-CSI report payload size.
UE 115-c may receive signaling (e.g., RRC signaling) indicative of
whether to consider a presence of the at least one of the SR or the
P-CSI report, or both, in selecting the PUCCH format. In some
examples the UE 115-c may receive signaling (e.g., RRC signaling)
indicative of the threshold, such as a communication resource
capacity associated with a PUCCH format (e.g., one or more bit
capacities associated with the PUCCH format, a bit capacity in
combination with a coding rate or coding factor, etc.).
At 430, UE 115-c may then transmit the uplink control message
(e.g., in the TTI, in the subframe, etc.) using the selected PUCCH
format. In some cases, the uplink control message may include the
HARQ payload and the SR payload; or the HARQ payload, the SR
payload and the P-CSI payload.
FIG. 5 shows a block diagram of a wireless device 500 that supports
P-CSI reporting for eCA in accordance with various aspects of the
present disclosure. Wireless device 500 may be an example of
aspects of a UE 115 described with reference to FIGS. 1-4. Wireless
device 500 may include a receiver 505, a PUCCH manager 510, or a
transmitter 515. Wireless device 500 may also include a processor.
Each of these components may be in communication with one
another.
The receiver 505 may receive information such as packets, user
data, or control information associated with various information
channels (e.g., control channels, data channels, and information
related to P-CSI reporting for eCA, etc.). Information may be
passed on to the PUCCH manager 510, and to other components of
wireless device 500. In some examples, the receiver 505 may receive
signaling indicative of the size of the HARQ payload from a base
station. In some examples, the receiver 505 may receive signaling
indicative of whether consider a presence of the at least one of
the SR or the P-CSI report in the selection of the PUCCH format. In
some examples, the signaling includes RRC signaling.
The PUCCH manager 510 may detect a size of a HARQ payload for
reporting (e.g., in a TTI, in a subframe, etc.) HARQ feedback
associated with multiple scheduled CCs, determine that at least one
of a SR or a periodic channel state information (P-CSI) report is
present, select a PUCCH format from a set of PUCCH formats based on
a comparison of a size of an uplink control message with a
threshold, where the uplink control message includes the HARQ
payload and a payload for at least one of the SR or the P-CSI
report, and transmit (e.g. in cooperation with the transmitter 515)
the uplink control message (e.g., in the TTI, in the subframe,
etc.) using the selected PUCCH format.
The transmitter 515 may transmit signals received from other
components of wireless device 500. In some examples, the
transmitter 515 may be collocated with the receiver 505 in a
transceiver module. The transmitter 515 may include a single
antenna, or it may include multiple antennas. In some examples, the
transmitter 515 may transmit the uplink control message using the
selected PUCCH format.
FIG. 6 shows a block diagram of a wireless device 600 that supports
P-CSI reporting for eCA in accordance with various aspects of the
present disclosure. Wireless device 600 may be an example of
aspects of a wireless device 500 or a UE 115 described with
reference to FIGS. 1-5. Wireless device 600 may include a receiver
505-a, a PUCCH manager 510-a, or a transmitter 515-a. Wireless
device 600 may also include a processor. Each of these components
may be in communication with one another. The PUCCH manager 510-a
may also include a HARQ size detection module 605, a PUCCH content
detection module 610, and a format selection module 615.
The receiver 505-a may receive information which may be passed on
to PUCCH manager 510-a, and to other components of wireless device
600. The PUCCH manager 510-a may perform the operations described
with reference to FIG. 5. The transmitter 515-a may transmit
signals received from other components of wireless device 600.
The HARQ size detection module 605 may detect a size of a HARQ
payload for reporting (e.g., in a TTI, in a subframe, etc.) HARQ
feedback associated with multiple scheduled CCs as described with
reference to FIGS. 2-4. The PUCCH content detection module 610 may
determine that at least one of a SR or a periodic channel state
information (P-CSI) report is present (e.g., to be included in the
TTI, to be included in the subframe, etc.) as described with
reference to FIGS. 2-4. In some examples, determining that at least
one of the SR or the P-CSI report may be present includes
determining whether a P-CSI report type of a set of P-CSI report
types may be present. In some examples, the set of P-CSI report
types at least includes P-CSI report types that support rank
indicator (RI) feedback or wideband PMI feedback.
The format selection module 615 may select a PUCCH format from a
set of PUCCH formats based on a comparison of a size of an uplink
control message with a threshold. The uplink control message may,
for instance, include the HARQ payload and a payload for the SR or
the P-CSI report, or both, as described with reference to FIGS.
2-4. In some examples, the set of PUCCH formats includes a first
set of PUCCH formats associated with one CC, a second set of PUCCH
formats associated with up to five CCs, or a third set of PUCCH
formats associated with more than five CCs. The format selection
module 615 may select the set of PUCCH formats based on a number of
CCs in the multiple scheduled CCs. The format selection module 615
may also determine whether to base the PUCCH format selection on
the presences of the SR or the P-CSI report, depending upon which
set of PUCCH formats is selected.
In some examples, selecting the PUCCH format includes selecting the
third set of PUCCH formats (e.g., PUCCH formats associated with and
that support UCI for more than five CCs). The third set of PUCCH
formats may be selected based on the size of the uplink control
message exceeding the threshold, for instance. In some examples,
the uplink control message includes the HARQ payload and the SR
payload. In some examples, the uplink control message includes the
HARQ payload, the SR payload, and the P-CSI payload. Additionally
or alternatively, the PUCCH format may be selected based on a
scaled P-CSI report payload size. In some examples, the uplink
control message may be associated with a cell group among multiple
cell groups.
FIG. 7 shows a block diagram 700 of a PUCCH manager 510-b that
supports P-CSI reporting for eCA in accordance with various aspects
of the present disclosure. The PUCCH manager 510-b may be an
example of aspects of a PUCCH manager 510 described with reference
to FIGS. 5-6, and may be a component of a UE 115, a wireless device
500, or a wireless device 600 as described with reference to FIGS.
1-6. The PUCCH manager 510-b may include a HARQ size detection
module 605-a, a PUCCH content detection module 610-a, and a format
selection module 615-a. Each of these modules may perform the
functions described with reference to FIG. 6. The PUCCH manager
510-b may also include a PUCCH multiplexer 705, a CSI configuration
module 710, and a CSI prioritization module 715.
The PUCCH multiplexer 705 may multiplex a HARQ payload with P-CSI
reports for two or more CCs configured for a UE, where a
determining that at least one of an SR or a P-CSI report is present
(e.g., to be included in an uplink control message) includes
identifying P-CSI reports for the two or more CCs configured for
the UE, as described with reference to FIGS. 2-4.
The CSI configuration module 710 may receive (e.g., in cooperation
with a receiver) a configuration supporting transmission of
multiple P-CSI reports during a TTI (e.g., a subframe), and the
multiple P-CSI reports may be associated with two or more of P-CSI
reports for multiple subframe sets of a CSI process, P-CSI reports
for multiple CSI processes of a CC, or P-CSI reports for multiple
CCs of a CA configuration as described with reference to FIGS. 2-4.
In some examples, the configuration supporting transmission of the
multiple P-CSI reports includes a CoMP configuration, a CA
configuration with one or more PUCCH groups, a dual-connectivity
configuration, or an IMTA configuration. In some examples, the CA
configuration includes a configuration of more than five CCs (e.g.,
an eCA configuration).
The CSI prioritization module 715 may determine that two or more
P-CSI reports are due for transmission during a TTI as described
with reference to FIGS. 2-4. The CSI prioritization module 715 may
transmit (e.g., in cooperation with a transmitter) at least one of
the P-CSI reports during the TTI according to a prioritization
rule. In some examples, the prioritization rule may be performed
based on a payload capacity or payload sizes of the two or more
P-CSI reports. In some examples, the payload capacity may be based
on a PUCCH format. In some examples, the prioritization rule
includes prioritizing a CSI type, followed by a CSI process ID,
followed by a CC index, followed by a subframe set index. The
prioritization may be performed within a CC, across CCs, or a
combination thereof.
FIG. 8 shows a diagram of a system 800, including a UE 115-d, that
supports P-CSI reporting in eCA in accordance with various aspects
of the present disclosure. UE 115-d may be an example of a wireless
device 500, a wireless device 600, or a UE 115 described with
reference to FIGS. 1-7. UE 115-d may include a PUCCH manager 810,
which may be an example of a PUCCH manager 510 described with
reference to FIGS. 5-7. UE 115-d may also include an eCA module
825, which may enable eCA operations as described with reference to
FIG. 1, such as operations involving a large number of CCs. UE
115-d may also include components for bi-directional voice and data
communications including components for transmitting communications
and components for receiving communications. For example, UE 115-d
may communicate bi-directionally with base station 105-d.
UE 115-d may also include a processor 805, and memory 815
(including software/firmware code 820), a transceiver 835, and one
or more antenna(s) 840, each of which may communicate, directly or
indirectly, with one another (e.g., via buses 845). The transceiver
835 may communicate bi-directionally, via the antenna(s) 840 or
wired or wireless links, with one or more networks, as described
above. For example, the transceiver 835 may communicate
bi-directionally with a base station 105-d. The transceiver 835 may
include a modem to modulate the packets and provide the modulated
packets to the antenna(s) 840 for transmission, and to demodulate
packets received from the antenna(s) 840. While UE 115-d may
include a single antenna 840, UE 115-d may also have multiple
antennas 840 capable of concurrently transmitting or receiving
multiple wireless transmissions.
The memory 815 may include random access memory (RAM) and read only
memory (ROM). The memory 815 may store computer-readable,
computer-executable software/firmware code 820 including
instructions that, when executed, cause the processor 805 to
perform various functions described herein (e.g., P-CSI reporting
for eCA, etc.). Alternatively, the software/firmware code 820 may
not be directly executable by the processor 805 but cause a
computer (e.g., when compiled and executed) to perform functions
described herein. The processor 805 may include an intelligent
hardware device, (e.g., a central processing unit (CPU), a
microcontroller, an application specific integrated circuit (ASIC),
etc.)
The components of wireless device 500, wireless device 600, PUCCH
manager 510, and system 800 may, individually or collectively, be
implemented with at least one ASIC adapted to perform some or all
of the applicable functions in hardware. Alternatively, the
functions may be performed by one or more other processing units
(or cores), on at least one integrated circuit (IC). In other
examples, other types of integrated circuits may be used (e.g.,
Structured/Platform ASICs, a field programmable gate array (FPGA),
or another semi-custom IC), which may be programmed in any manner
known in the art. The functions of each unit may also be
implemented, in whole or in part, with instructions embodied in a
memory, formatted to be executed by one or more general or
application-specific processors.
FIG. 9 shows a flowchart illustrating a method 900 for P-CSI
reporting for eCA in accordance with various aspects of the present
disclosure. The operations of method 900 may be implemented by a UE
115, a wireless device 500, or a wireless device 600, or their
components, as described with reference to FIGS. 1-8. For example,
the operations of method 900 may be performed by the PUCCH manager
510 as described with reference to FIGS. 5-8. In some examples, a
UE 115 may execute a set of instructions to control the functional
elements of the UE 115 to perform the functions described below.
Additionally or alternatively, the UE 115 may perform aspects the
functions described below using special-purpose hardware.
At block 905, the UE 115 may detect a size of a HARQ payload for
reporting (e.g., in a TTI, in a subframe, etc.) HARQ feedback
associated with transmissions on a set of CCs, as described with
reference to FIGS. 2-4. In some examples, operations of block 905
may be performed by a HARQ size detection module 605 as described
with reference to FIG. 6 or 7.
At block 910, the UE 115 may determine that at least one of a SR or
a periodic channel state information (P-CSI) report is present
(e.g., to be included in the TTI, to be included in the subframe,
etc.), as described with reference to FIGS. 2-4. In some cases,
determining that the SR or the P-CSI report is present includes
determining to report a subset of P-CSI reports from a set of P-CSI
reports. In some examples, operations of block 910 may be performed
by a PUCCH content detection module 610 as described with reference
to FIG. 6 or 7.
At block 915, the UE 115 may select a PUCCH format from a set of
PUCCH formats based at least in part on a comparison of a size of
an uplink control message with a threshold, where the uplink
control message includes the HARQ payload and a payload for at
least one of the SR or the P-CSI report, as described with
reference to FIGS. 2-4. In some examples, operations of block 915
may be performed by a format selection module 615 as described with
reference to FIG. 6 or 7.
At block 920, the UE 115 may transmit the uplink control message
(e.g., in the TTI, in the subframe, etc.) using the selected PUCCH
format, as described with reference to FIGS. 2-4. In some examples,
operations of block 920 may be performed by a transmitter 515 as
described with reference to FIGS. 5-6, or a transceiver 835
described with reference to FIG. 8.
FIG. 10 shows a flowchart illustrating a method 1000 for P-CSI
reporting in eCA in accordance with various aspects of the present
disclosure. The operations of method 1000 may be implemented by a
UE 115, a wireless device 500, or a wireless device 600, or their
components, as described with reference to FIGS. 1-8. For example,
the operations of method 1000 may be performed by the PUCCH manager
510 as described with reference to FIGS. 5-8. In some examples, a
UE 115 may execute a set of instructions to control the functional
elements of the UE 115 to perform the functions described below.
Additionally or alternatively, the UE 115 may perform aspects the
functions described below using special-purpose hardware. The
method 1000 may also incorporate aspects of method 900 described
with reference to FIG. 9.
At block 1005, the UE 115 may detect a size of a HARQ payload for
reporting (e.g., in a TTI, in a subframe, etc.) HARQ feedback
associated with transmissions on a set of CCs, as described with
reference to FIGS. 2-4. In some examples, operations of block 1005
may be performed by a HARQ size detection module 605 as described
with reference to FIG. 6 or 7.
At block 1010, the UE 115 may determine that at least one of a SR
or a periodic channel state information (P-CSI) report is present
(e.g., to be included in the TTI, to be included in the subframe,
etc.), as described with reference to FIGS. 2-4. In some examples,
operations of block 1010 may be performed by a PUCCH content
detection module 610 as described with reference to FIG. 6 or
7.
At block 1015, the UE 115 may select a set of PUCCH formats based
at least in part on a number of CCs in the multiple scheduled CCs,
as described with reference to FIGS. 2-4. In some examples,
operations of block 1015 may be performed by a format selection
module 615 as described with reference to FIG. 6 or 7.
At block 1020, the UE 115 may determine whether a size of the
payload for the at least one of the SR or P-CSI report is included
in the size of the uplink control message for the comparison with
the threshold based at least in part on the selected set of PUCCH
formats, as described with reference to FIGS. 2-4. In some
examples, operations of block 1020 may be performed by a format
selection module 615 as described with reference to FIG. 6 or
7.
At block 1025, the UE 115 may select a PUCCH format from the set of
PUCCH formats based at least in part on a comparison of a size of
an uplink control message with a threshold, where the uplink
control message includes the HARQ payload and a payload for at
least one of the SR or the P-CSI report, as described with
reference to FIGS. 2-4. In some cases, selecting the PUCCH format
includes selecting a PUCCH format from a set of PUCCH formats
associated with reporting HARQ feedback for more than 5 CCs based
at least in part on the size of the uplink control message
exceeding the threshold. In some examples, operations of block 1025
may be performed by a format selection module 615 as described with
reference to FIG. 6 or 7.
At block 1030, the UE 115 may transmit the uplink control message
(e.g., in the TTI, in the subframe, etc.) using the selected PUCCH
format, as described with reference to FIGS. 2-4. In some examples,
operations of block 1030 may be performed by a transmitter 515 as
described with reference to FIG. 5-6, or a transceiver 835 as
described with reference to FIG. 8.
FIG. 11 shows a flowchart illustrating a method 1100 for P-CSI
reporting in eCA in accordance with various aspects of the present
disclosure. The operations of method 1100 may be implemented by a
UE 115, a wireless device 500, or a wireless device 600, or their
components, as described with reference to FIGS. 1-8. For example,
the operations of method 1100 may be performed by the PUCCH manager
510 as described with reference to FIGS. 5-8. In some examples, a
UE 115 may execute a set of instructions to control the functional
elements of the UE 115 to perform the functions described below.
Additionally or alternatively, the UE 115 may perform aspects the
functions described below using special-purpose hardware. The
method 1100 may also incorporate aspects of methods 900, and 1000
described with reference to FIGS. 9-10.
At block 1105, the UE 115 may detect a size of a HARQ payload for
reporting (e.g., in a TTI, in a subframe, etc.) HARQ feedback
associated with transmissions on a set of CCs, as described with
reference to FIGS. 2-4. In some examples, operations of block 1105
may be performed by a HARQ size detection module 605 as described
with reference to FIG. 6 or 7.
At block 1110, the UE 115 may determine that at least one of a SR
or a periodic channel state information (P-CSI) report is present
(e.g., to be included in the TTI, to be included in the subframe,
etc.), as described with reference to FIGS. 2-4. In some examples,
operations of block 1110 may be performed by a PUCCH content
detection module 610 as described with reference to FIG. 6 or
7.
At block 1115, the UE 115 may multiplex the HARQ payload with P-CSI
reports for two or more CCs configured for the UE 115, where
determining that at least one of an SR or a P-CSI report is present
includes identifying the P-CSI reports for the two or more CCs
configured for the UE 115, as described with reference to FIGS.
2-4. In some examples, operations of block 1125 may be performed by
a PUCCH multiplexer 705 as described with reference to FIG. 7.
At block 1120, the UE 115 may select a PUCCH format from a set of
PUCCH formats based at least in part on a comparison of a size of
an uplink control message with a threshold, where the uplink
control message includes the HARQ payload and a payload for at
least one of the SR or the P-CSI report, as described with
reference to FIGS. 2-4. In some examples, operations of block 1115
may be performed by a format selection module 615 as described with
reference to FIG. 6 or 7.
At block 1125, the UE 115 may transmit (e.g., in the TTI, in the
subframe, etc.) the uplink control message using the selected PUCCH
format as described with reference to FIGS. 2-4. In some examples,
operations of block 1120 may be performed by transmitter 515 as
described with reference to FIGS. 5-6, or a transceiver 835 as
described with reference to FIG. 8.
FIG. 12 shows a flowchart illustrating a method 1200 for P-CSI
reporting in eCA in accordance with various aspects of the present
disclosure. The operations of method 1200 may be implemented by a
UE 115, a wireless device 500, or a wireless device 600, or their
components, as described with reference to FIGS. 1-8. For example,
the operations of method 1200 may be performed by the PUCCH manager
510 as described with reference to FIGS. 5-8. In some examples, a
UE 115 may execute a set of instructions to control the functional
elements of the UE 115 to perform the functions described below.
Additionally or alternatively, the UE 115 may perform aspects the
functions described below using special-purpose hardware. The
method 1200 may also incorporate aspects of methods 900, 1000, and
1100 described with reference to FIGS. 9-11.
At block 1205, the UE 115 may detect a size of a HARQ payload for
reporting (e.g., in a TTI, in a subframe, etc.) HARQ feedback
associated with transmission on multiple scheduled CCs as described
with reference to FIGS. 2-4. In some examples, operations of block
1205 may be performed by a HARQ size detection module 605 as
described with reference to FIG. 6 or 7.
At block 1210, the UE 115 may determine that at least one of a SR
or a periodic channel state information (P-CSI) report is present
(e.g., to be included in the TTI, to be included in the subframe,
etc.) as described with reference to FIGS. 2-4. In some examples,
operations of block 1210 may be performed by a PUCCH content
detection module 610 as described with reference to FIG. 6 or
7.
At block 1215, the UE 115 may select a PUCCH format from a set of
PUCCH formats based at least in part on a comparison of a size of
an uplink control message with a threshold, where the uplink
control message includes the HARQ payload and a payload for at
least one of the SR or the P-CSI report as described with reference
to FIGS. 2-4. In some examples, operations of block 1215 may be
performed by a format selection module 615 as described with
reference to FIG. 6 or 7.
At block 1220, the UE 115 may transmit the uplink control message
(e.g., in the TTI, in the subframe, etc.) using the selected PUCCH
format as described with reference to FIGS. 2-4. In some examples,
operations of block 1220 may be performed by a transmitter 515 as
described with reference to FIGS. 5-6, or a transceiver 835 as
described with reference to FIG. 8.
FIG. 13 shows a flowchart illustrating a method 1300 for P-CSI
reporting in eCA in accordance with various aspects of the present
disclosure. The operations of method 1300 may be implemented by a
UE 115, a wireless device 500, or a wireless device 600, or their
components, as described with reference to FIGS. 1-8. For example,
the operations of method 1300 may be performed by the PUCCH manager
510 as described with reference to FIGS. 5-8. In some examples, a
UE 115 may execute a set of instructions to control the functional
elements of the UE 115 to perform the functions described below.
Additionally or alternatively, the UE 115 may perform aspects the
functions described below using special-purpose hardware. The
method 1300 may also incorporate aspects of methods 900, 1000,
1100, and 1200 described with reference to FIGS. 9-12.
At block 1305, the UE 115 may receive a configuration supporting
transmission of multiple periodic channel state information (P-CSI)
reports during a TTI, where the multiple P-CSI reports are
associated with two or more of P-CSI reports for multiple subframe
sets of a CSI process, P-CSI reports for multiple CSI processes of
a CC, or P-CSI reports for multiple CCs of a CA configuration as
described with reference to FIGS. 2-4. In some examples, operations
of block 1305 may be performed by a CSI configuration module 710 as
described with reference to FIG. 7.
At block 1310, the UE 115 may determine two or more P-CSI reports
due for transmission during a TTI as described with reference to
FIGS. 2-4. In some examples, operations of block 1310 may be
performed by a CSI prioritization module 715 as described with
reference to FIG. 7.
At block 1315, the UE 115 may transmit at least one of the P-CSI
reports during the TTI according to a prioritization rule as
described with reference to FIGS. 2-4. In some examples, operations
of block 1315 may be performed by a CSI prioritization module 715
as described with reference to FIG. 7.
Thus, methods 900, 1000, 1100, 1200, and 1300 may provide for P-CSI
reporting in eCA. It should be noted that methods 900, 1000, 1100,
1200, and 1300 describe possible implementation, and that the
operations and the steps may be rearranged or otherwise modified
such that other implementations are possible. In some examples,
aspects from two or more of the methods 900, 1000, 1100, 1200, and
1300 may be combined.
The description herein provides examples, and is not limiting of
the scope, applicability, or examples set forth in the claims.
Changes may be made in the function and arrangement of elements
discussed without departing from the scope of the disclosure.
Various examples may omit, substitute, or add various procedures or
components as appropriate. Also, features described with respect to
some examples may be combined in other examples.
Techniques described herein may be used for various wireless
communications systems such as code division multiple access
(CDMA), time division multiple access (TDMA), frequency division
multiple access (FDMA), orthogonal frequency division multiple
access (OFDMA), single carrier frequency division multiple access
(SC-FDMA), and other systems. The terms "system" and "network" are
often used interchangeably. A code division multiple access (CDMA)
system may implement a radio technology such as CDMA2000, Universal
Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000,
IS-95, and IS-856 standards. IS-2000 Releases 0 and A are commonly
referred to as CDMA2000 1.times., 1.times., etc. IS-856 (TIA-856)
is commonly referred to as CDMA2000 1.times.EV-DO, High Rate Packet
Data (HRPD), etc. UTRA includes Wideband CDMA (WCDMA) and other
variants of CDMA. A time division multiple access (TDMA) system may
implement a radio technology such as Global System for Mobile
Communications (GSM). An orthogonal frequency division multiple
access (OFDMA) system may implement a radio technology such as
Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), IEEE 802.11
(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA
and E-UTRA are part of Universal Mobile Telecommunications system
(UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are
new releases of Universal Mobile Telecommunications System (UMTS)
that use E-UTRA. UTRA, E-UTRA, Universal Mobile Telecommunications
System (UMTS), LTE, LTE-A, and Global System for Mobile
communications (GSM) are described in documents from an
organization named "3rd Generation Partnership Project" (3GPP).
CDMA2000 and UMB are described in documents from an organization
named "3rd Generation Partnership Project 2" (3GPP2). The
techniques described herein may be used for the systems and radio
technologies mentioned above as well as other systems and radio
technologies. The description herein, however, describes an LTE
system for purposes of example, and LTE terminology is used in much
of the description above, although the techniques are applicable
beyond LTE applications.
In LTE/LTE-A networks, including such networks described herein,
the term evolved node B (eNB) may be generally used to describe the
base stations. The wireless communications system or systems
described herein may include a heterogeneous LTE/LTE-A network in
which different types of evolved node B (eNBs) provide coverage for
various geographical regions. For example, each eNB or base station
may provide communication coverage for a macro cell, a small cell,
or other types of cell. The term "cell" can be used to describe a
base station, a carrier or CC associated with a base station, or a
coverage area (e.g., sector, etc.) of a carrier or base station,
depending on context.
Base stations may include or may be referred to by those skilled in
the art as a base transceiver station, a radio base station, an
access point, a radio transceiver, a NodeB, eNodeB (eNB), Home
NodeB, a Home eNodeB, or some other suitable terminology. The
geographic coverage area for a base station may be divided into
sectors making up only a portion of the coverage area. The wireless
communications system or systems described herein may include base
stations of different types (e.g., macro or small cell base
stations). The UEs described herein may be able to communicate with
various types of base stations and network equipment including
macro eNBs, small cell eNBs, relay base stations, and the like.
There may be overlapping geographic coverage areas for different
technologies.
A macro cell generally covers a relatively large geographic area
(e.g., several kilometers in radius) and may allow unrestricted
access by UEs with service subscriptions with the network provider.
A small cell is a lower-powered base station, as compared with a
macro cell, that may operate in the same or different (e.g.,
licensed, unlicensed, etc.) frequency bands as macro cells. Small
cells may include pico cells, femto cells, and micro cells
according to various examples. A pico cell, for example, may cover
a small geographic area and may allow unrestricted access by UEs
with service subscriptions with the network provider. A femto cell
may also cover a small geographic area (e.g., a home) and may
provide restricted access by UEs having an association with the
femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for
users in the home, and the like). An eNB for a macro cell may be
referred to as a macro eNB. An eNB for a small cell may be referred
to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An
eNB may support one or multiple (e.g., two, three, four, and the
like) cells (e.g., CCs). A UE may be able to communicate with
various types of base stations and network equipment including
macro eNBs, small cell eNBs, relay base stations, and the like.
The wireless communications system or systems described herein may
support synchronous or asynchronous operation. For synchronous
operation, the base stations may have similar frame timing, and
transmissions from different base stations may be approximately
aligned in time. For asynchronous operation, the base stations may
have different frame timing, and transmissions from different base
stations may not be aligned in time. The techniques described
herein may be used for either synchronous or asynchronous
operations.
The downlink transmissions described herein may also be called
forward link transmissions while the uplink transmissions may also
be called reverse link transmissions. Each communication link
described herein--including, for example, wireless communications
system 100 and 200 of FIGS. 1 and 2--may include one or more
carriers, where each carrier may be a signal made up of multiple
sub-carriers (e.g., waveform signals of different frequencies).
Each modulated signal may be sent on a different sub-carrier and
may carry control information (e.g., reference signals, control
channels, etc.), overhead information, user data, etc. The
communication links described herein (e.g., communication links 125
of FIG. 1) may transmit bidirectional communications using
frequency division duplex (FDD) (e.g., using paired spectrum
resources) or time division duplex (TDD) operation (e.g., using
unpaired spectrum resources). Frame structures may be defined for
frequency division duplex (FDD) (e.g., frame structure type 1) and
TDD (e.g., frame structure type 2).
The description set forth herein, in connection with the appended
drawings, describes example configurations and does not represent
all the examples that may be implemented or that are within the
scope of the claims. The term "exemplary" used herein means
"serving as an example, instance, or illustration," and not
"preferred" or "advantageous over other examples." The detailed
description includes specific details for the purpose of providing
an understanding of the described techniques. These techniques,
however, may be practiced without these specific details. In some
instances, well-known structures and devices are shown in block
diagram form in order to avoid obscuring the concepts of the
described examples.
As used herein, the phrase "based on" shall not be construed as a
reference to a closed set of conditions. For example, an exemplary
step that is described as "based on condition A" may be based on
both a condition A and a condition B without departing from the
scope of the present disclosure. In other words, as used herein,
the phrase "based on" shall be construed in the same manner as the
phrase "based at least in part on."
In the appended figures, similar components or features may have
the same reference label. Further, various components of the same
type may be distinguished by following the reference label by a
dash and a second label that distinguishes among the similar
components. If just the first reference label is used in the
specification, the description is applicable to any one of the
similar components having the same first reference label
irrespective of the second reference label.
Information and signals described herein may be represented using
any of a variety of different technologies and techniques. For
example, data, instructions, commands, information, signals, bits,
symbols, and chips that may be referenced throughout the above
description may be represented by voltages, currents,
electromagnetic waves, magnetic fields or particles, optical fields
or particles, or any combination thereof.
The various illustrative blocks and modules described in connection
with the disclosure herein may be implemented or performed with a
general-purpose processor, a digital signal processor (DSP), an
ASIC, an FPGA or other programmable logic device, discrete gate or
transistor logic, discrete hardware components, or any combination
thereof designed to perform the functions described herein. A
general-purpose processor may be a microprocessor, but in the
alternative, the processor may be any conventional processor,
controller, microcontroller, or state machine. A processor may also
be implemented as a combination of computing devices (e.g., a
combination of a digital signal processor (DSP) and a
microprocessor, multiple microprocessors, one or more
microprocessors in conjunction with a DSP core, or any other such
configuration).
The functions described herein may be implemented in hardware,
software executed by a processor, firmware, or any combination
thereof. If implemented in software executed by a processor, the
functions may be stored on or transmitted over as one or more
instructions or code on a computer-readable medium. Other examples
and implementations are within the scope of the disclosure and
appended claims. For example, due to the nature of software,
functions described above can be implemented using software
executed by a processor, hardware, firmware, hardwiring, or
combinations of any of these. Features implementing functions may
also be physically located at various positions, including being
distributed such that portions of functions are implemented at
different physical locations. Also, as used herein, including in
the claims, "or" as used in a list of items (for example, a list of
items prefaced by a phrase such as "at least one of" or "one or
more of") indicates an inclusive list such that, for example, a
list of at least one of A, B, or C means A or B or C or AB or AC or
BC or ABC (i.e., A and B and C).
Computer-readable media includes both non-transitory computer
storage media and communication media including any medium that
facilitates transfer of a computer program from one place to
another. A non-transitory storage medium may be any available
medium that can be accessed by a general purpose or special purpose
computer. By way of example, and not limitation, non-transitory
computer-readable media can include RAM, ROM, electrically erasable
programmable read only memory (EEPROM), compact disk (CD) ROM or
other optical disk storage, magnetic disk storage or other magnetic
storage devices, or any other non-transitory medium that can be
used to carry or store desired program code means in the form of
instructions or data structures and that can be accessed by a
general-purpose or special-purpose computer, or a general-purpose
or special-purpose processor. Also, any connection is properly
termed a computer-readable medium. For example, if the software is
transmitted from a website, server, or other remote source using a
coaxial cable, fiber optic cable, twisted pair, digital subscriber
line (DSL), or wireless technologies such as infrared, radio, and
microwave, then the coaxial cable, fiber optic cable, twisted pair,
digital subscriber line (DSL), or wireless technologies such as
infrared, radio, and microwave are included in the definition of
medium. Disk and disc, as used herein, include CD, laser disc,
optical disc, digital versatile disc (DVD), floppy disk and Blu-ray
disc where disks usually reproduce data magnetically, while discs
reproduce data optically with lasers. Combinations of the above are
also included within the scope of computer-readable media.
The description herein is provided to enable a person skilled in
the art to make or use the disclosure. Various modifications to the
disclosure will be readily apparent to those skilled in the art,
and the generic principles defined herein may be applied to other
variations without departing from the scope of the disclosure.
Thus, the disclosure is not to be limited to the examples and
designs described herein but is to be accorded the broadest scope
consistent with the principles and novel features disclosed
herein.
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